I spoke to "Richard", this am., about the possibility of writing a cnc. program, to port these, and possibly 910-920 Lotus heads ? Currently, the volume is not there, to justify. "IF",enough interest could be generated between JHPS and Lotus customers, this would save all concerned time/money, for a more consistant finished product. I will be needing (2) such heads, for my build, but to make this work, will take genuine request, for cnc porting of customers heads. Perhaps a "request list ". I have NO affiliation with Richard, for this consideration. Cheers, Art G.

I've just got my Cnc ported head back from Gary Kemp in the UK.
Anyway I told him of the lotus bit heads and I also told him of the mob I found in North Hampton who have a 907 CNC ported head on their web site.
Turns out the North Hampton guys are ex f1 engineers of ilmor racing. And have set up a company that specialise in CNC ported heads modelled in computational fluid dynamics (cfd) anyway after conversations I arranged for a head I bought in the uk through a mate in London to be shipped to Garry for inspection. He then shipped it to the guys in Northhampton who then fitted Garry's oversize race valves inlet and exhaust plus new valve seats ( as the valve spec is so much larger that you can not simply recut the existing seat) then the carried out the CNC porting. Then they installed the new guides ( supplied by Gary) then they carried out a CNC multi angle valve seat cut. All modelled then flow benched to prove the model at various lifts. But costly. For the money I could have purchased a billet steel 2.2 crank from QED.
But all for the love of my 907!